Answers

Select Run as Administrator and accept the UAC prompt - the Elevated Command Prompt window should pop up.

At the Command prompt, type

CHKDSK C: /R

and hit the Enter key.

You will be told that the drive is locked,

and the CHKDSK will run at he next boot - hit the Y key, and then reboot.

The chkdsk will take a few hours depending on the sizeof the drive, so be patient!

After the CHKDSK has run, Windows should boot normally(possibly after a second auto-reboot) - then run the SFC.

SFC -System File Checker - Instructions

Click on Start > All Programs > Accessories

Right-click on the Command Prompt entry

Select Run as Administrator and accept the UAC prompt - the Elevated Command Prompt window should pop up.

At the Command prompt, type

SFC /SCANNOW

and hit the Enter key

Wait for the scan to finish - make a note of any error messages - and then reboot.

Copy the CBS.log file created to your desktop (you can't manipulate it directly) and then compress the copy and upload it to your SkyDrive (http://skydrive.live.com
) and post a link to it so that I can take a look.